Field of the Invention
The invention relates to a technology for detecting an object moving in the periphery of a vehicle.
Description of the Background Art
Conventionally, object detection systems each of which detects an object by use of the shot image of the periphery of a vehicle captured by a camera have been proposed. In an example, an object detection system detects an object based on the shot image captured by a front camera, and displays on a display an indication or the like that shows the detected result. By use of such an object detection system, a user (mainly a driver) can easily perceive the object such as another vehicle approaching from the location that the user cannot see at an intersection with a poor view, a parking area or the like.
A frame correlation method that uses a plurality of shot images captured at successive times is known as a method for detecting an object on such an object detection system. In an example, an optical flow method that is one of the frame correlation methods extracts feature points from each of the plurality of shot images (frames), and then detects an object based on the directions of the optical flows that show the move of the feature points among the plurality of shot images.
The frame correlation method described above, however, has the characteristics that it is more difficult to detect an object accurately when the vehicle where the object detection system is installed is running at a relatively high velocity or turning. Therefore, a conventional object detection system stops the operation of a detector such as ASIC that detects an object so as to disable the detection function when detection accuracy is not ensured based on the velocity or the steering angle of the vehicle.
However, once the operation of the detector is stopped, restarting the detector is needed when the detection function is again enabled. In general, such restarting the detector requires a certain period of time (approximately one second) as an initialization processing. Therefore, there may be a case that the detection result by the detector is not obtained even when the object detection is needed.